Yes, Bird outplayed Erving in that 1981 series. Erving outplayed Bird in 1980 and 1982.
Let's not forget that in all three years 1980-82, the Celtics had home court advantage and were favored to win the series. The 76ers took 2 out of 3. They were unfortunate in that the years they won, they had to play the Lakers. The year they lost, the Celtics advanced and got to play a .500 Rockets team in the Finals.